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Coffee & Chocolate
A Beginners Guide to Specialty Coffee, Knowledge
How to extract light roast filter coffee
If you’ve ever brewed a light roast that smelled amazing but tasted sour, watery, bitter, or dry, you’ve met the real boss of filter coffee: Extraction.
In this post we’ll explain what extraction is, and give you a simple way to answer the most useful dialing question:
Do I need more extraction, or more even extraction?
So what is coffee extraction?
Extraction is what happens when hot water pulls flavor stuff out of coffee grounds.
That “flavor stuff” is called coffee solids, tiny bits of acids, sugars, bitters, and aromatics that dissolve into the water and become your cup of coffee.
A helpful image:
Think of coffee grounds like a sponge full of flavor. Water moves through, grabs some of that flavor, and carries it into your mug.
What’s important to know, is that not everything comes out at the same speed. Some flavors dissolve quickly. Others take more time and heat.
That’s why the same coffee can taste:
- sharp and sour when not enough has dissolved
- bitter and drying when too much (or the wrong parts) dissolve
- sweet and balanced when you hit the happy zone
Extraction is a balance problem
Extraction in itself is not “good” or “bad. It’s about how much and how evenly you pull out.
If you get too little extraction you may taste:
- sour/lemony sharpness without sweetness
- “watery” or hollow flavor
- sometimes “green/vegetal” or “peanut/nutty” notes
If you get too much extraction you may taste:
- bitterness that lingers
- a dry, rough feeling (astringent)
- harshness or “too sharp” edges
The “fun” part begins when the cup tastes both sour and dry.
That’s when “even extraction” becomes the real issue.
A very useful question is: do I need more extraction or more even extraction?
When the flavor is off, don’t panic and change everything. Ask:
1) Do I need more extraction?
This means: I’m not pulling enough flavor overall.
It usually tastes like:
- sour without sweetness
- hollow / “watery” (even if it smells great)
- short finish (flavor disappears fast)
The brew often behaves like:
- runs fast and finishes quickly
- doesn’t stall or choke
- looks fairly normal/even in the filter bed
2) Do I need more even extraction?
This means: some grounds are extracting too little and others too much at the same time.
It usually tastes like:
- sour at first, but dry/rough or bitter at the end
- confusing cup: “both under and over”
- flavors feel muddy instead of clear
The brew often behaves like:
- stalls or chokes unexpectedly
- drawdown is inconsistent from brew to brew
- you see sludge/mud on top (lots of fines)
- the bed looks uneven, cracked, or “donut-shaped”
How to diagnose in 60 seconds (no equipment needed)
Use this tiny checklist after your next brew:
Step A: Taste
Pick the best match:
Mostly sour / hollow / watery → likely more extraction
Sour + dry / harsh / bitter at once → likely more even extraction
Step B: Observe the brew
Fast and clean flow supports “more extraction.”
Stalling, muddy bed, inconsistent flow supports “more even extraction.”
Stalling, muddy bed, inconsistent flow supports “more even extraction.”
What to change
You can change many things: temperature, grind, agitation, ratio, contact time, filters…
But the easiest path is to change one thing at a time, in a sensible order.
If you need more extraction
Start with the safest levers:
1. Increase slurry temperature
(Preheat your brewer/server well, use hotter water, rinse the filter with hot water.)
2. Grind slightly finer
3. Increase contact time gently
(Often happens naturally when you grind a touch finer.)
If you need more even extraction
Your goal is smoother, more consistent flow and fewer “over vs under” zones.
Start here:
1. Use less agitation.
Skip stirring. Do just a gentle swirl if needed for wetting.
2. Grind a touch coarser
This often reduces fines problems and helps water flow more evenly.
3. Pour more gently and consistently
(Lower pour height, steady stream, avoid “dumping” water.)
4. Consider your filter.
Some filters drain faster/slower and change how fines behave.
Some filters drain faster/slower and change how fines behave.
Read more about filters here.
A quick two-brew test (my favorite way to learn fast)
If you’re unsure which problem you have, do this:
Brew the same recipe twice:
Brew 1: improve heat (preheat more / slightly hotter water)
Brew 2: reduce agitation (no stirring, gentler pour)
If Brew 1 gets sweeter and rounder → you needed more extraction.
If Brew 2 gets cleaner and less dry/harsh → you needed more even extraction.
If Brew 2 gets cleaner and less dry/harsh → you needed more even extraction.
This teaches you more than ten random adjustments.
The takeaway
Extraction is simply water pulling flavor out of grounds, and great coffee comes from getting the right amount, evenly. Next time your brew tastes off, don’t change everything. Ask:
More extraction… or more even extraction?
Then change one thing and taste again.